Patent GB-686541-A (GB)
Abstract: 686,541. Calculating-apparatus. GRANGE, T. June 27, 1949 [June 28, 1948; Sept. 23, 1948], Nos. 16992/49 and 16993/49. Cla-ss 106 (i). A calculating-machine for the four rules comprises a frame, a keyboard incorporated with said frame for entering the numbers, a selection stop or set-bar controlled by each key of said keyboard, an ordinarly shiftable factor carriage movable transversely upon said frame, selection racks movable parallel to one another upon the carriage in a direction perpendicular to the plane in which the selection stops move, means for displacing each selection rack until it encounters a corresponding stop, a numbers drum driven by each selection rack, mechanism for advancing said carriage actuated upon depression of a key to displace the carriage for one decimal place, calculating racks longitudinally slidable upon the frame and engaging the corresponding selection racks, each calculating rack consisting of two opposed sets of teeth, a retaining rack carried by each calculating - rack, a counting-wheel located between said two sets of teeth of the calculating racks, adapted to engage either set of teeth to effect addition or subtraction and a tens carry-over mechanism operated by the counting-wheel. The machine has a ten-key keyboard, Figs. 1, 3 and 5, each key 4 having a stem 3 with an offset lug 5, Fig. 4, which upon depression of a key depresses an associated setbar 7. The set-bar 7 moves transversely relatively to the rods 11 which pass through slots 8 in the bar against the pressure of a spring 10, Fig. 3. The carriage 12, Figs. 1, 3 and 5, having sides 12<SP>1</SP>, 12<SP>2</SP>, Figs. 1 and 3, is transversely movable on bars 13 under the control of an escapement mechanism, described later, and supports longitudinally slidable selection racks 17, Figs. 1 and 5, urged to the right by springs 18 but normally held stationary by pawls 20, Fig. 5. Situated outside the set-bars 7, Figs. 3 and 7, is a pair of levers 27 which upon depression of a key 4 are moved downwardly by the depressed set-bar 7. A bar 28 carried by the levers 27 thereupon releases the first pawl 20 from the first rack 17 which is then moved by its spring 18 until arrested by a projection 9, Fig. 5, on the depressed set-bar 7. Upon release of the depressed key the pawl 20 locks the first rack 17 in its new position. The keys 4 may not be integral with the stems 3 but may act thereon through pivoted levers, Fig. 6 (not shown). Escapement mechanism. The downward movement of the levers 27, Fig. 7, is transmitted by a rod 31 to a bar 30 which effects downward movement of an escapement plate 33, Fig. 3. The plate 33 carries two pawls 36, 38 which co-operate with the teeth 37<SP>1</SP>, 37<SP>2</SP>, respectively of an escapement rack 37 to effect, in the usual way, step-by-step movement to the left of the carriage 12. An arm 46<SP>3</SP> of an L- shaped lever 46, Fig. 1, is attached to the carriage 12 and is urged clockwise about the pivot 46<SP>2</SP> so as to urge the carriage 12 to the left. An item indicator 48, Figs. 1 and 5, is operated by the racks 17. The totalizer actuating means comprises a group of double racks 58, 59, Fig. 5, each of which has an extension 62 having a guide slot 63 for a rod 64 attached to a corresponding pawl 65 urged to the left by a spring 65<SP>2</SP>. The carriage 12 carries a cammed plate 69, Fig. 24, which depresses the pawls 65 associated with the racks 17 which have been set by depression of the keys. The depressed pawls 65 are engaged by a rake 72, Fig. 5, which is reciprocated each machine cycle. Each pair of racks 58, 59, co-operates with a totalizer actuator gear 80 which drives the corresponding totalizer wheel 84, Figs. 1 and 5, through a gear 83, Fig. 5. The shaft 85 of the totalizer 84 and the shaft 86 of the gears 80 are supported by a pair of levers 87, Figs. 1 and 15, arranged for vertical movement in guides 90, 91. Each lever 87 carries a roller 92 which rides in an adjacent cammed slot 93 in a reciprocable member 94 or 95. The members 94, 95 are interconnected for unitary movement. The slots 93 are so shaped as to effect raising or lowering from the normal neutral position of the levers 87 to engage the gears 80, Fig. 5, with the rack 58 or 59 for adding or subtracting, when the members 94, 95, Figs. 1 and 15, are moved rearwardly or forwardly. The member 95 carries two rollers 348, 349, Fig. 15, which engage respectively in one of two slots in the members 342, 343 longitudinally slidable on fixed rollers 340, 341 and urged to the right and left, respectively, by springs 344, 345 so that the members 94, 95 are urged to their neutral positions. The main shaft 150, Fig. 1, may be rotated manually or by a motor and during a revolution thereof a cam 191 effects forward or rearward movement of the members 94, 95 in dependence of the position of an intermediate member controlled by the operator. During a machine cycle a slide 147 carrying the rake 72 is reciprocated by an arm 148 on the main shaft 150. Addition. The first number is registered by operation of the appropriate keys 4, Fig. 5, to set up on the racks 17 and the item indicator 48, as described above. The appropriate pawls 65 are depressed by the plate 69 of the carriage 12 and the main shaft 150, Fig. 1, is given a revolution to reciprocate the member 147 and the rake 72, Fig. 5. The rake 72 in its travel to the right meets and carries along the depressed pawls 65 and their associated racks 58, 59 until the racks abut the parts 17<SP>4</SP> of the racks 17 which have been set. The cam 191 then moves the members 94, 95, Fig. 15, to the rear so raising the levers 87 and bringing the gears 80, Fig. 5, into mesh with the racks 58. During the return of the racks to the left the number is therefore entered into the totalizer 84. The racks 17 are then returned by a bail to their initial positions and the item counter 48 zeroized. The addend is then set on the racks 17 and the item counter 48 as before. The main shaft 150 is given a second revolution and the addend is entered into the totalizer 84 by the racks 58. Transfer mechanism. This comprises a group of reciprocable forks 103, Fig. 5, one for each but the last actuator rack 58, 59. Each fork has teeth 106, 107 which co-operate with respective transfer teeth 81, 82 of the adjacent gear 80. A pawl 110 pivoted to the fork 103 normally presses a pawl 113 downwardly against the pressure of a spring 114. When a tooth 81, 82 of a gear 80 moves the adjacent fork 103 to the left the pawl 110 frees the pawl 113 to engage the projection 592 of the next higher rack 58, 59 so that on movement to the left of the pawl 113 by an associated pawl 115 actuated by a cam 120 on a shaft 121 controlled by the mechanism shown in Fig. 9 by a cam 190 on the main shaft 150, the said next higher rack 58, 59 is moved one step to the left. Subtraction. This is performed in similar manner to addition. The minuend is set up in the totalizer 84 as before. The intermediate mechanism, Fig. 16 (not shown), between the cam 191, Fig. 1, and the members 94, 95, Figs. 1 and 15, is then set by the operator so that the members 94, 95 are, in the succeeding machine cycle, moved to the right, Fig. 15, and the gears 80 brought into mesh with the racks 59. Multiplication and division. These operations are effected by repeated subtraction and multiplication by repeated addition. The revolutions counter or quotient indicator comprises a set of numeral wheels 241, Figs. 1 and 22, and associated ratchets 247. The member 147, Fig. 21; which is reciprocated every machine cycle, carries a ramp 275 which as the member 147 moves to the right meets a roller 268 and thereby moves a lever 266 to rock a lever 263 and move a cross-piece 258 and a finger 272 which is attached to the carriage 12 and which through linkage moves a pawl 251 which steps on the appropriate ratchet-wheel 247 and its numeral wheel 241. During an over-subtract cycle the highest order actuator rack 58, 59 is moved and through a linkage effects transverse movement of the cross-piece 258 so that the lever 263 on next rocking clockwise. Fig. 21, passes through a slot 262 in the cross-piece which therefore remains stationary and so the pawl 251 is not actuated. The numeral wheels 241 may be returned to zero by manuallyoperated means. The member 147, Fig. 1, carries a pawl 175, the position of which may be controlled by the operator so that during the end cycle of a multiplication when the member 147 moves rearwardly the pawl 175 meets the arm 461 of the lever 46 which is moved counterclockwise to return the carriage 12. The carriage shift during a multiplication is effected by movement of a rack 400, Fig. 3, which co-operates with a pawl 403 carried by the carriage 12. The machine may have as shown in Fig. 1 a second keyboard and associated actuators whereby the number of cycles made by the machine during a multiplication are automatically controlled. The keys 423-431 co-operate with actuators which are differentially set in accordance with the value of the associated key. A main switch for the driving motor is closed by the movement of an actuator which has teeth which are engaged by a pawl. During each cycle the pawl steps back the actuator until it is returned to its initial position.